Is it necessary to bring witnesses when complaining about an accuser of slander, and is it permissible to waive the Hadd (punishment) for slander in exchange for financial compensation?

Qadhf (slanderous accusation) is accusing someone of zina (unlawful sexual intercourse) or liwat (sodomy). Islamic law has severely prohibited it, considering it one of the major sins. It has imposed strict penalties on the accuser (qadhif) if he does not produce four witnesses, including: eighty lashes, never accepting his testimony, and deeming him a fasiq (transgressor). It is not permissible to waive the hadd (prescribed penalty) for qadhf in exchange for a sum of money, because it is not permissible to compensate for one's honor with money, just as it is not permissible to demand financial compensation after the hadd has been carried out on the accuser.